Fluid compressor

ABSTRACT

An apparatus includes an electric motor including a rotor and a stator, and a compression device including a compression chamber and a compression mechanism. The compression chamber is within either the rotor or the stator of the electric motor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to U.S. Application No. 62/068,375, filed Oct. 24, 2014, the entire content of which is incorporated into the present application by reference.

FIELD OF THE INVENTION

The present subject matter relates generally to a fluid compressor. In particular, it relates to a fluid compressor in which the fluid being compressed is compressed in a compression chamber within the motor driving the compressor.

BACKGROUND OF THE INVENTION

Present fluid compressors generally include a compression chamber for compressing the fluid, and a separate electric motor to drive the apparatus that compresses the fluid in the compression chamber. Including these two separate mechanisms causes the overall structure to be bulky and costly. Accordingly, the present inventors sought out a way to include the compression apparatus inside the electric motor that drives the compression apparatus.

SUMMARY OF THE INVENTION

One aspect of the present invention broadly comprises a compressor including an electric motor including a rotor and a stator; and a compression device including a compression chamber and a compression mechanism. The compression chamber is within either the rotor or the stator of the electric motor.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present subject matter, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 illustrates a perspective view of one embodiment of the present invention;

FIG. 2 is a side cutaway view of the embodiment shown in FIG. 1;

FIG. 3 illustrates a perspective view of the embodiment shown in FIG. 1 with the parts disassembled from each other;

FIG. 4 illustrates a top view of the compression chamber at a start of the compression cycle;

FIGS. 5-7 illustrate a top view of the compression chamber at subsequent points of the compression cycle;

FIG. 8 illustrates a top view of the compression chamber at an end of the compression cycle;

FIG. 9 illustrates a perspective view of the rotor showing the cooling fluid fan and a cooling fluid inlet hole;

FIG. 10 illustrates an aspect of the present invention embodied as an axial compressor;

FIG. 11 illustrates an aspect of the present invention embodied as a scroll compressor;

FIGS. 12A-12G illustrates a first embodiment of the seal of the present invention;

FIG. 13A-13F illustrates the movement of the seal ring in the embodiment shown in FIGS. 12A-12G;

FIG. 14 shows a view of the bearings of one embodiment of the invention;

FIGS. 15 and 15A illustrates a second embodiment of the seal of the present invention;

FIGS. 16 and 16A illustrates an embodiment of a bearing of the present invention;

FIGS. 17A-17E illustrates the second embodiment of the seal of the present invention;

FIGS. 18A-18G illustrates a third embodiment of the seal of the present invention; and

FIG. 19 shows a top view of an embodiment of the invention with the compression chamber inside the stator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference is presently made in detail to exemplary embodiments of the present subject matter, one or more examples of which are illustrated in or represented by the drawings. Each example is provided by way of explanation of the present subject matter, not limitation of the present subject matter. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present subject matter without departing from the scope or spirit of the present subject matter. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present subject matter covers such modifications and variations as come within the scope of the disclosure and equivalents thereof.

FIGS. 1-9 depict a first embodiment of a rotary compressor. However, the present invention can be applied to many other types of compressors including and not limited to: turbine compressors, scroll compressors, axial compressors, and screw compressors. For example, FIGS. 10 and 11 depict aspects the present invention embodied as an axial compressor and a scroll compressor, respectively. These figures show that compression mechanisms 200 are located within electric motors 250 of their respective compressors. Each of these figures show a compressor including a compression mechanism inside either a rotor or a stator of the electric motor driving the compression mechanism, which is one aspect of the present invention.

In the embodiment shown in FIGS. 1-9, rotary compressor 100 includes a housing 10 made of lower housing 12, main housing 14, and upper housing 16. Lower housing 12 includes fluid intake 13 and upper housing 16 includes fluid exit 17. The embodiment shown in FIGS. 1-9 includes three housing portions bolted together, but other configurations are possible as known in the art. The modifications are within the scope of the invention.

In FIGS. 1-9, the housing contains a shaft 20 for a motor 30 including stator 32 and rotor 34. Shaft 20 includes a lower hollow portion 22 that receives gas from intake 13 to be compressed. Shaft 20 also includes an upper hollow portion 24 that receives compressed fluid to be communicated through valve 40 to fluid exit 17. Further, shaft 20 includes a slot 26 that receives a leaf spring 27 and a vane 28.

Electric motor 30 may be a single speed, multispeed, or variable speed motor. Further, electric motor 30 may be any type of electric motor including and not limited to an induction motor, a permanent magnet motor, a brushless DC motor, and a switched reluctance motor.

When the rotor 34 turns as a result of current flowing through the motor 30, vane 28 will move forward and back within slot 26 due to biasing by leaf spring 27. The outer edge of vane 28 will remain in contact with the inner surface of the compression chamber 36, which is within rotor 34. Compression chamber 36 has a cross-section of approximately a circle when viewed along the shaft direction, but a center of compression chamber 36 is offset from a center of shaft 20. Accordingly, compression chamber 36 rotates eccentrically around a center of shaft 20 during each compression cycle, as shown in FIGS. 4-8.

Although FIGS. 1-9 show that the biasing of the vane 28 is done with leaf spring 27, this biasing may also be done by a coiled spring, or gas or fluid pressure, such as the gas or fluid within the compressor. These modifications are also within the scope of the invention.

At the start of a cycle as shown in FIG. 4, vane 28 divides lower hollow portion 22 from upper hollow portion 24 such that fluid at first enters compression chamber 36, but cannot flow directly to fluid exit 17. As the rotor 34 rotates, the vane causes the volume that the fluid can access to shrink, compressing the fluid, as shown in FIGS. 5-7. As the rotor 34 continues to rotate and compress the fluid, upper hollow portion 24 becomes accessible to the fluid, as shown in FIG. 8. The now compressed fluid can then travel out of the compression chamber 36 by passing through valve 40.

The outer wall of compression chamber 36 is a solid sleeve 36A (labeled in FIG. 14) such as metal to prevent the fluid from escaping. This is in contrast to conventional electric motor rotors which may only contain laminate structures. In particular, solid sleeve 36A may be made of steel.

In the embodiment shown in FIGS. 1-9, the compressor may have a displacement of 10 in³. In other embodiments, the compressor may have a displacement of 0.5 to 200 in³. In embodiments of the invention using scroll compressors, higher displacements are more efficient. Finally, at very big displacements, the invention may be embodied using a screw compressor. The compressor in FIGS. 1-9 may compress a refrigerant fluid such as an R-400 series or R-500 series refrigerant. Other fluids may be compressed as well, and these modifications are all within the scope of the invention. Further, portions of the compressor components may extend beyond the length of the rotor and/or stator to allow greater displacements independent of the dimensions of the rotor and stator. For example, FIG. 10 shows an axial compressor in which compression mechanism 200 extends in the length direction beyond the end of electric motor 250 at both ends.

In one embodiment of the present invention, the rotor also includes a cooling fluid fan 50 for driving cooling fluid through the rotor 34 to cool the portions within. FIG. 9 shows that cooling fluid fan 50 includes vanes 52, one of which has a hole 54 at a base thereof. Each vane is at an acute angle with respect to the top of rotor 34, such that a vane with a hole 54 at its base can catch and drive cooling fluid outside the rotor 34 into the hole 54. Rotor 34 may have passages therein in communication with hole 54 to allow the cooling fluid to penetrate and cool the internal rotor parts. The cooling fluid can then exit the rotor through hole 56 (labeled in FIG. 14) on a lower surface of rotor 34. The cooling fluid may be oil, refrigerant, or lubricating fluid or a combination of these fluids.

FIG. 9 shows a rotor 34 with a single hole 54 at the base of one of six vanes 52. However, in other embodiments, multiple vanes 52 may have holes at their base, such as each of 6 vanes having a hole at their base. Further, the angle between the top of rotor 34 and each oil vane may be between 0 and 90 degrees. All of these modifications are within the scope of the invention.

FIGS. 12A-12G shows close-ups of the first embodiment of seal 80 shown in FIG. 1. Seal 80 includes upper race 82, lower race 84, seal ring 86, and o-rings 88 and 89. Upper race 82 includes an annular groove 82A around an outer perimeter and an annular groove 82B around an inner perimeter. Lower race 84 includes an annular groove 84A around an inner perimeter and an annular groove 84B around an inner perimeter. O-ring 88 is located in groove 82B to frictionally seal the upper race 82 to the shaft such that upper race 82 rotates with the rotor. O-ring 89 is located in groove 84B to seal the interface between the lower race 84 and the upper bearing cup 92 (labeled in FIG. 14). Seal ring 86 is initially located in groove 82A of the upper race when the motor is off. However, as the motor runs, split 86A in seal ring 86 allows seal ring 86 to increase in diameter as the rotor spins, which then causes the seal ring to at least partially enter groove 84A of the lower race 84, as shown in FIGS. 13A-13F. This allows the seal ring to prevent any contaminants from passing through the interface between the upper and lower races.

FIG. 14 shows a close-up of the bearings 90A and 90B. In the embodiment shown in FIGS. 1-9 and 12-14, bearings 90A and 90B are bronze, oil lubricated, sleeve drawn bushings. However, other bearings are possible, such as magnetic, oil-less, and sealed roller bearings. All of these modifications are within the scope of the invention.

Upper bearing 90A supports the upper end of rotor 34, and lower bearing 90B supports the lower end of rotor 34. Bearings 90A and 90B are located much closer together than conventional bearings. As shown in FIG. 14, each of bearings 90A and 90B extend within the opening at each end of rotor 34 into the central passage of the rotor 34 where shaft 20 is located. This allows for a more stable running condition and less load on the bearings. Further, they have a larger diameter and are longer in length than conventional bearings, which provides more support than conventional bearings. As shown in FIG. 14, the upper bearing 90A is adjacent the upper bearing cup 92, which may be made of steel. The lower bearing 90B is adjacent the lower bearing cup 94, which also may be made of steel. In the embodiment shown in FIG. 14, rotor 34 may include aluminum rotor end rings 34A which are roughly even in height with the bearings 90A and 90B, while the portion of rotor 34 between the bearings 90A and 90B may be steel laminations 34B. As noted previously, rotor 34 also include steel sleeve 36A which provides the outer boundary of compression chamber 36.

FIGS. 15 and 15A show a second embodiment of a seal of the present invention. Seal 180 includes an outer race 184 and an inner race 182, shown in FIG. 17A. Inner race 182 includes surface 182A that contacts surface 184A of outer race 184. This provides a seal to prevent oil from leaking out of the compressor. The angle of surface 182A and 184A may be, for example, 20° with respect to the vertical. However, other configurations are within the scope of the invention as claimed. In the embodiment shown in FIGS. 15 and 15A, o-rings are located in grooves in the inner surface of the inner race and the outer surface of the outer race.

FIGS. 16 and 16A show an embodiment of a sealed bearing of the present invention. Bearing 280 includes metal spheres 282 located between inner race 286 and outer race 284.

FIGS. 18A-18G illustrate a third embodiment of the seal of the present invention. Seal 380 includes inner race 382, outer race 384, and seal ring 388. Outer race 384 includes surface 384A which contacts seal ring 388, and inner race 382 includes surface 382A which also contacts seal ring 388. Accordingly, seal ring 388 can prevent oil from leaking out through the interface between the inner and outer races. In one embodiment, surfaces 382A and 384A make an angle of 45° with respect to the vertical. However, other configurations are within the scope of the invention as claimed.

FIG. 19 illustrates an embodiment of the invention where the compression chamber is inside the stator instead of the rotor, as shown in FIGS. 1-9. Compressor 500 includes compression chamber 536 inside stator 532, which is inside rotor 534. Vane 528 moves in and out of shaft 520 to expand and contract the side of compression chamber 536. Thus, a compressor with the compression chamber inside the stator can operate in a similar manner as the compressor shown in FIGS. 1-9.

The present written description uses examples to disclose the present subject matter, including the best mode, and also to enable any person skilled in the art to practice the present subject matter, including making and using any devices or systems and performing any incorporated and/or associated methods. While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art. 

1. An apparatus comprising: an electric motor including a rotor and a stator; and a compression device including a compression chamber and a compression mechanism, the compression chamber being within either the rotor or the stator of the electric motor.
 2. The apparatus according to claim 1, wherein the compression chamber is inside the rotor of the electric motor.
 3. The apparatus according to claim 1, wherein the compression chamber is inside the stator of the electric motor.
 4. The apparatus according to claim 1, further comprising: a seal including an inner race and an outer race.
 5. The apparatus according to claim 4, further comprising: a seal ring located between the inner race and the outer race and configured to change position when the electric motor is turned on.
 6. The apparatus according to claim 5, wherein the seal ring moves from a position in the inner race when the motor is off to a position partially within the outer race when the motor is turned on.
 7. The apparatus according to claim 4, further comprising: a plurality of metal spheres located between the inner race and the outer race.
 8. The apparatus according to claim 4, further comprising: a seal ring located in contact with a surface of the inner race and a surface of the outer race.
 9. An apparatus comprising: an electric motor including a rotor, a stator, and a shaft, the rotor including a central passage, at least a portion of the shaft being located in the central passage of the rotor; an upper bearing supporting an upper end of the rotor, the upper bearing extending into an upper portion of the central passage of the rotor; and a lower bearing supporting a lower end of the rotor, the lower bearing extending into a lower portion of the central passage of the rotor.
 10. An apparatus comprising: an electric motor including a rotor and a stator; and a seal including an upper race, a lower race, and a seal ring, the seal ring located in an annular groove in an outer perimeter of the upper race, the annular groove in the outer perimeter of the upper race being adjacent to an annular groove in an inner perimeter of the lower race such that when the upper race rotates with the rotor, the seal ring moves at least partly into the annular groove in the inner perimeter of the lower race to seal an interface between the upper and lower races. 